/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.iotdb.db.engine.memtable;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import org.apache.iotdb.db.conf.IoTDBDescriptor;
import org.apache.iotdb.db.engine.modification.Deletion;
import org.apache.iotdb.db.engine.modification.Modification;
import org.apache.iotdb.db.engine.querycontext.ReadOnlyMemChunk;
import org.apache.iotdb.db.exception.WriteProcessException;
import org.apache.iotdb.db.exception.metadata.MetadataException;
import org.apache.iotdb.db.exception.query.QueryProcessException;
import org.apache.iotdb.db.metadata.PartialPath;
import org.apache.iotdb.db.qp.physical.crud.InsertRowPlan;
import org.apache.iotdb.db.qp.physical.crud.InsertTabletPlan;
import org.apache.iotdb.db.rescon.TVListAllocator;
import org.apache.iotdb.db.utils.MemUtils;
import org.apache.iotdb.db.utils.datastructure.TVList;
import org.apache.iotdb.tsfile.file.metadata.enums.TSDataType;
import org.apache.iotdb.tsfile.file.metadata.enums.TSEncoding;
import org.apache.iotdb.tsfile.read.common.TimeRange;
import org.apache.iotdb.tsfile.write.schema.MeasurementSchema;

public abstract class AbstractMemTable implements IMemTable {

  private final Map<String, Map<String, IWritableMemChunk>> memTableMap;

  private long version = Long.MAX_VALUE;

  private List<Modification> modifications = new ArrayList<>();

  private int avgSeriesPointNumThreshold = IoTDBDescriptor.getInstance().getConfig()
      .getAvgSeriesPointNumberThreshold();

  /**
   * memory size of data points, including TEXT values
   */
  private long memSize = 0;

  /**
   * memory usage of all TVLists memory usage regardless of whether these TVLists are full,
   * including TEXT values
   */
  private long tvListRamCost = 0;

  /**
   * The initial value is true because we want calculate the text data size when recover
   * memTable!!
   */
  protected boolean disableMemControl = true;

  private int seriesNumber = 0;

  private long totalPointsNum = 0;

  private long totalPointsNumThreshold = 0;

  private long maxPlanIndex = Long.MIN_VALUE;

  private long minPlanIndex = Long.MAX_VALUE;

  public AbstractMemTable() {
    this.memTableMap = new HashMap<>();
  }

  public AbstractMemTable(Map<String, Map<String, IWritableMemChunk>> memTableMap) {
    this.memTableMap = memTableMap;
  }

  @Override
  public Map<String, Map<String, IWritableMemChunk>> getMemTableMap() {
    return memTableMap;
  }

  /**
   * check whether the given seriesPath is within this memtable.
   *
   * @return true if seriesPath is within this memtable
   */
  private boolean checkPath(String deviceId, String measurement) {
    return memTableMap.containsKey(deviceId) && memTableMap.get(deviceId).containsKey(measurement);
  }

  private IWritableMemChunk createIfNotExistAndGet(String deviceId, String measurement,
      MeasurementSchema schema) {
    if (!memTableMap.containsKey(deviceId)) {
      memTableMap.put(deviceId, new HashMap<>());
    }
    Map<String, IWritableMemChunk> memSeries = memTableMap.get(deviceId);
    if (!memSeries.containsKey(measurement)) {
      memSeries.put(measurement, genMemSeries(schema));
      seriesNumber++;
      totalPointsNumThreshold += avgSeriesPointNumThreshold;
    }
    return memSeries.get(measurement);
  }

  protected abstract IWritableMemChunk genMemSeries(MeasurementSchema schema);

  @Override
  public void insert(InsertRowPlan insertRowPlan) {
    updatePlanIndexes(insertRowPlan.getIndex());
    for (int i = 0; i < insertRowPlan.getValues().length; i++) {

      if (insertRowPlan.getValues()[i] == null) {
        continue;
      }

      Object value = insertRowPlan.getValues()[i];
      memSize += MemUtils.getRecordSize(insertRowPlan.getMeasurementMNodes()[i].getSchema().getType(), value,
          disableMemControl);

      write(insertRowPlan.getDeviceId().getFullPath(), insertRowPlan.getMeasurements()[i],
          insertRowPlan.getMeasurementMNodes()[i].getSchema(), insertRowPlan.getTime(), value);
    }

    totalPointsNum += insertRowPlan.getMeasurements().length - insertRowPlan.getFailedMeasurementNumber();
  }

  @Override
  public void insertTablet(InsertTabletPlan insertTabletPlan, int start, int end)
      throws WriteProcessException {
    updatePlanIndexes(insertTabletPlan.getIndex());
    try {
      write(insertTabletPlan, start, end);
      memSize += MemUtils.getRecordSize(insertTabletPlan, start, end, disableMemControl);
      totalPointsNum += (insertTabletPlan.getMeasurements().length - insertTabletPlan.getFailedMeasurementNumber())
        * (end - start);
    } catch (RuntimeException e) {
      throw new WriteProcessException(e);
    }
  }


  @Override
  public void write(String deviceId, String measurement, MeasurementSchema schema, long insertTime,
      Object objectValue) {
    IWritableMemChunk memSeries = createIfNotExistAndGet(deviceId, measurement, schema);
    memSeries.write(insertTime, objectValue);
  }

  @Override
  public void write(InsertTabletPlan insertTabletPlan, int start, int end) {
    updatePlanIndexes(insertTabletPlan.getIndex());
    for (int i = 0; i < insertTabletPlan.getMeasurements().length; i++) {
      if (insertTabletPlan.getColumns()[i] == null) {
        continue;
      }
      IWritableMemChunk memSeries = createIfNotExistAndGet(insertTabletPlan.getDeviceId().getFullPath(),
          insertTabletPlan.getMeasurements()[i], insertTabletPlan.getMeasurementMNodes()[i].getSchema());
      memSeries.write(insertTabletPlan.getTimes(), insertTabletPlan.getColumns()[i],
          insertTabletPlan.getDataTypes()[i], start, end);
    }
  }

  @Override
  public boolean checkIfChunkDoesNotExist(String deviceId, String measurement) {
    if (!memTableMap.containsKey(deviceId)) {
      return true;
    }
    Map<String, IWritableMemChunk> memSeries = memTableMap.get(deviceId);
    return !memSeries.containsKey(measurement);
  }

  @Override
  public int getCurrentChunkPointNum(String deviceId, String measurement) {
    Map<String, IWritableMemChunk> memSeries = memTableMap.get(deviceId);
    IWritableMemChunk memChunk = memSeries.get(measurement);
    return memChunk.getTVList().size();
  }

  public int getSeriesNumber() {
    return seriesNumber;
  }

  public long getTotalPointsNum() {
    return totalPointsNum;
  }

  @Override
  public long size() {
    long sum = 0;
    for (Map<String, IWritableMemChunk> seriesMap : memTableMap.values()) {
      for (IWritableMemChunk writableMemChunk : seriesMap.values()) {
        sum += writableMemChunk.count();
      }
    }
    return sum;
  }

  @Override
  public long memSize() {
    return memSize;
  }

  @Override
  public boolean reachTotalPointNumThreshold() {
    if (totalPointsNum == 0) {
      return false;
    }
    return totalPointsNum >= totalPointsNumThreshold;
  }

  @Override
  public void clear() {
    memTableMap.clear();
    modifications.clear();
    memSize = 0;
    seriesNumber = 0;
    totalPointsNum = 0;
    totalPointsNumThreshold = 0;
    tvListRamCost = 0;
    maxPlanIndex = 0;
  }

  @Override
  public boolean isEmpty() {
    return memTableMap.isEmpty();
  }

  @Override
  public ReadOnlyMemChunk query(String deviceId, String measurement, TSDataType dataType,
      TSEncoding encoding, Map<String, String> props, long timeLowerBound)
      throws IOException, QueryProcessException, MetadataException {
    if (!checkPath(deviceId, measurement)) {
      return null;
    }
    List<TimeRange> deletionList = constructDeletionList(deviceId, measurement, timeLowerBound);
    IWritableMemChunk memChunk = memTableMap.get(deviceId).get(measurement);
    TVList chunkCopy = memChunk.getTVList().clone();

    chunkCopy.setDeletionList(deletionList);
    return new ReadOnlyMemChunk(measurement, dataType, encoding, chunkCopy, props, getVersion());
  }

  private List<TimeRange> constructDeletionList(String deviceId, String measurement,
      long timeLowerBound) throws MetadataException {
    List<TimeRange> deletionList = new ArrayList<>();
    deletionList.add(new TimeRange(Long.MIN_VALUE, timeLowerBound));
    for (Modification modification : modifications) {
      if (modification instanceof Deletion) {
        Deletion deletion = (Deletion) modification;
        if (deletion.getPath().matchFullPath(new PartialPath(deviceId, measurement))
            && deletion.getEndTime() > timeLowerBound) {
          long lowerBound = Math.max(deletion.getStartTime(), timeLowerBound);
          deletionList.add(new TimeRange(lowerBound, deletion.getEndTime()));
        }
      }
    }
    return TimeRange.sortAndMerge(deletionList);
  }

  @Override
  public void delete(PartialPath originalPath, PartialPath devicePath, long startTimestamp, long endTimestamp) {
    Map<String, IWritableMemChunk> deviceMap = memTableMap.get(devicePath.getFullPath());
    if (deviceMap == null) {
      return;
    }

    Iterator<Entry<String, IWritableMemChunk>> iter = deviceMap.entrySet().iterator();
    while (iter.hasNext()) {
      Entry<String, IWritableMemChunk> entry = iter.next();
      IWritableMemChunk chunk = entry.getValue();
      PartialPath fullPath = devicePath.concatNode(entry.getKey());
      if (originalPath.matchFullPath(fullPath)) {
        if (startTimestamp == Long.MIN_VALUE && endTimestamp == Long.MAX_VALUE) {
          iter.remove();
        }
        int deletedPointsNumber = chunk.delete(startTimestamp, endTimestamp);
        totalPointsNum -= deletedPointsNumber;
      }
    }
  }

  @Override
  public void delete(Deletion deletion) {
    this.modifications.add(deletion);
  }

  public long getVersion() {
    return version;
  }

  public void setVersion(long version) {
    this.version = version;
  }

  @Override
  public void addTVListRamCost(long cost) {
    this.tvListRamCost += cost;
  }

  @Override
  public long getTVListsRamCost() {
    return tvListRamCost;
  }

  @Override
  public void addTextDataSize(long testDataSize) {
    this.memSize += testDataSize;
  }

  @Override
  public void release() {
    for (Entry<String, Map<String, IWritableMemChunk>> entry : memTableMap.entrySet()) {
      for (Entry<String, IWritableMemChunk> subEntry : entry.getValue().entrySet()) {
        TVListAllocator.getInstance().release(subEntry.getValue().getTVList());
      }
    }
  }

  @Override
  public long getMaxPlanIndex() {
    return maxPlanIndex;
  }

  @Override
  public long getMinPlanIndex() {
    return minPlanIndex;
  }

  void updatePlanIndexes(long index) {
    maxPlanIndex = Math.max(index, maxPlanIndex);
    minPlanIndex = Math.min(index, minPlanIndex);
  }
}
